So what happened is that the Yankees tested one of their hitters and found that all his home runs came off the "label" of the bat. So, they made a fully legal modification to maximize his performance.
They also redistributed some of the weight of the bat to the sweet spot for more pop. It was created by a former Yankees employee who went to MIT. Bat was submitted to MLB and approved before the season.
Go Yanks! 3-0
